
#include <math.h>

int add(int a, int b) {
    return a + b;
}

double multiply(double a, double b) {
    return a * b;
}

double distance(Point p1, Point p2) {
    double dx = p2.x - p1.x;
    double dy = p2.y - p1.y;
    return sqrt(dx*dx + dy*dy);
}